Powder supplying and laying integrated scraper device for 3D printing and single-scraper bidirectional powder laying method

Abstract

The invention relates to a powder supply and laying integrated scraper device for 3D printing and a single-scraper bidirectional powder laying method.The powder supply and laying integrated scraper device comprises a powder supply device and a scraper frame, the powder supply device comprises a powder supply shaft, a gear and a rack, a plurality of powder supply grooves are formed in the circumference of the powder supply shaft, and each powder supply groove is formed in the axial direction of the powder supply shaft; the gears are installed at the two ends of the powder supply shaft, the racks are fixed to the left side plate and the right side plate of the forming chamber, the gears are located above the racks, the gears are meshed with the racks, and the gears rotate to drive the powder supply shaft to rotate clockwise and anticlockwise. The powder supply shaft is installed on a scraper frame, a front powder falling opening and a rear powder falling opening are formed in the scraper frame, and a scraper is arranged below the scraper frame. A powder falling and distributing structure is omitted, powder supply and scraper powder laying are integrated, the problem of uneven powder distribution is effectively solved, and it is guaranteed that during two-way powder laying, the problem of powder shortage does not exist in the two directions; and breakover of the powder groove before and after switching is canceled, powder is prevented from still falling into a forming area after powder laying, and the powder laying quality is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and in particular relates to an integrated scraper device for supplying and spreading powder for 3D printing and a single-scraper bidirectional powder spreading method. Background Art

[0002] Additive manufacturing (also known as laser selective melting or metal 3D printing) technology is a new processing method that has emerged in recent years. The raw materials used in this technology are all powders of tens to hundreds of microns. During the forming process, the powder is evenly spread on the forming substrate through a powder supply device and a powder spreading device, and then a laser or other energy source is used to melt the powder in a specific geometric shape area on the surface to produce a metallurgical bond, and finally the parts are grown layer by layer to achieve a three-dimensional forming process.

[0003] In the 3D printing process, the powder supply device and the powder spreading device are important components of the equipment. Existing powder supply devices mostly adopt the upper and lower powder dropping method, and the powder spreading device mostly adopts the single scraper two-way powder spreading method. In order to achieve single scraper two-way powder spreading, most powder spreading devices are equipped with front and rear powder slots. When spreading powder forward, the front powder slot is connected; when spreading powder backward, the rear powder slot is connected. This also requires the powder supply device to be equipped with a powder distribution structure to evenly distribute the powder to the front and rear powder slots.

[0004] However, since powder distribution is affected by powder fluidity, it is not possible to achieve uniform powder distribution in the front and rear powder slots, which may lead to a lack of powder when spreading the powder on the side with less powder. This can only be solved by increasing the amount of powder falling, but this will cause powder waste and require frequent replacement of the overflow powder tank. At the same time, the front and rear powder slots need to be switched during the powder spreading process, which will also cause powder jamming and leakage. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention proposes an integrated scraper device for powder supply and spreading and a single-scraper bidirectional powder spreading method for 3D printing. The device can realize powder falling during the powder spreading process, effectively solving the problem of uneven powder distribution, and does not require switching of the front and rear powder troughs, effectively improving the powder spreading quality.

[0006] The present invention is implemented as follows: an integrated scraper device for powder supply and spreading for 3D printing includes a powder supply device and a scraper frame, the powder supply device includes a powder supply shaft, a gear and a rack, the gear is installed at both ends of the powder supply shaft, the rack is fixed on the left and right side plates of a forming chamber, the gear is located above the rack, the gear is meshed with the rack, and the rotation of the gear drives the powder supply shaft to rotate clockwise and counterclockwise; the powder supply shaft is installed on the scraper frame, the scraper frame is provided with a front powder drop port and a rear powder drop port, and a scraper is provided below the scraper frame.

[0007] In the above technical solution, preferably, a plurality of powder supply grooves are arranged around the powder supply shaft, and each of the powder supply grooves is arranged along the axial direction of the powder supply shaft.

[0008] In the above technical solution, preferably, a powder dropping device is provided above the scraper frame, a powder supply tank is connected above the powder dropping device, and a lower powder dropping port of the powder dropping device is connected to a powder trough above the powder supply device.

[0009] In the above technical solution, preferably, a pressure sensor is provided in the powder trough above the powder supply device, and the pressure sensor is used to monitor the amount of powder in the powder trough.

[0010] In the above technical solution, preferably, a forming platform is provided in the forming chamber, a front powder overflow device and a rear powder overflow device are provided at the front and rear sides of the forming platform respectively, and a piston is provided at the lower middle part.

[0011] The method for performing single-scraper bidirectional powder spreading using the above device comprises the following steps:

[0012] S1. The integrated scraper device for powder supply and spreading stays at the initial position for powder spreading, and the powder dropping device drops an appropriate amount of metal powder, so that the powder slot above the powder supply device has the required amount of powder for two layers of printing;

[0013] S2, the integrated scraper device for powder supply and spreading starts to move forward. When the integrated scraper device for powder supply and spreading moves to the meshing of the gear and the rack, the gear rotates clockwise, driving the powder supply shaft to rotate clockwise, and the metal powder in the powder supply groove falls from the front powder drop port onto the forming platform. The scraper scrapes the fallen metal powder to spread it evenly on the forming area, realizing powder supply and spreading while moving forward, until the integrated scraper device for powder supply and spreading moves to the front end, scraping the excess metal powder into the front overflow powder device;

[0014] S3, the laser starts printing metal powder;

[0015] S4. After the printing is completed, the integrated scraper device for powder supply and spreading starts to move backward. When the integrated scraper device for powder supply and spreading moves to the meshing of the gear and the rack, the gear rotates counterclockwise, driving the powder supply shaft to rotate counterclockwise, and the metal powder in the powder supply groove falls from the rear powder drop port onto the forming platform. The scraper scrapes the fallen metal powder to make it evenly spread on the forming area, realizing powder supply and spreading while moving backward, until the integrated scraper device for powder supply and spreading moves to the rear end, and scrapes the excess metal powder into the rear overflow powder device;

[0016] S5, the laser starts printing metal powder; at the same time, the integrated scraper device for powder spreading stays at the initial position of powder spreading, and the powder dropping device drops an appropriate amount of metal powder;

[0017] S5. After printing is completed, the integrated scraper device for powder spreading moves forward again, and steps S2-S5 are repeated until the printing task is completed.

[0018] The advantages and positive effects of the present invention are:

[0019] The present invention eliminates the powder falling and powder separation structure, and replaces it with an integrated powder supply and scraper powder spreading, which effectively solves the problem of uneven powder distribution and ensures that there is no powder shortage in both directions during bidirectional powder spreading. The conduction of the front and rear powder troughs is cancelled to avoid powder still falling into the forming area after powder spreading, which effectively improves the powder spreading quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the integrated powder supply and spreading scraper device provided by an embodiment of the present invention in the initial position of powder spreading;

[0021] Figure 2 It is a schematic diagram of the structure of the integrated powder supply and spreading scraper device provided in an embodiment of the present invention spreading powder forward;

[0022] Figure 3 It is a schematic structural diagram of the powder supply and spreading integrated scraper device provided in an embodiment of the present invention spreading powder backwards;

[0023] Figure 4 1 is a schematic diagram of the structure of an integrated powder supply and spreading scraper device provided in an embodiment of the present invention (the rack is not shown);

[0024] Figure 5 is a cross-sectional view of a powder supply and spreading integrated scraper device provided in an embodiment of the present invention;

[0025] Figure 6 It is a schematic diagram of the structure of a powder supply shaft provided in an embodiment of the present invention.

[0026] In the figure: 1. powder dropping device; 2. metal powder; 3. powder supply device; 4. gear; 5. scraper holder; 6. scraper; 7. forming platform; 8. rear overflow powder device; 9. piston; 10. workpiece; 11. front overflow powder device; 12. rack; 13. pressure sensor; 14. powder supply shaft; 14-1, powder supply groove. DETAILED DESCRIPTION

[0027] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0028] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] See also Figure 1 to Figure 6 An embodiment of the present invention provides an integrated powder supply and spreading scraper device for 3D printing, including a powder supply device 3 and a scraper frame 5, the powder supply device 3 includes a powder supply shaft 14, a gear 4 and a rack 12, the gear 4 is installed at both ends of the powder supply shaft 14, the rack 12 is fixed on the left and right side plates of the forming chamber, the gear 4 is located above the rack 12, the gear 4 is meshed with the rack 12, and the rotation of the gear 4 drives the powder supply shaft 14 to rotate clockwise and counterclockwise; the powder supply shaft 14 is installed on the scraper frame 5, the scraper frame 5 is provided with a front powder drop port and a rear powder drop port, and a scraper 6 is provided below the scraper frame 5.

[0031] Specifically, a plurality of powder supply grooves 14 - 1 are arranged around the powder supply shaft 14 , and each of the powder supply grooves 14 - 1 is arranged along the axial direction of the powder supply shaft 14 , so as to ensure that the powder supply shaft 14 can continuously supply powder to the forming platform 7 .

[0032] A powder dropping device 1 is arranged above the scraper frame 5, and a powder supply tank is connected to the powder dropping device 1. The powder dropping port of the powder dropping device 1 is connected to the powder trough above the powder supply device 3, so that the powder in the powder supply tank falls into the powder trough.

[0033] A pressure sensor 13 is provided in the powder trough above the powder supply device 3 , and the pressure sensor 13 is used to monitor the amount of powder in the powder trough.

[0034] A forming platform 7 is provided in the forming chamber, a front powder overflow device 11 and a rear powder overflow device 8 are provided at the front and rear sides of the forming platform 7, and a piston 9 is provided at the lower middle part.

[0035] The specific principle is as follows: the powder dropping device 1 is a fixed part, connected to the powder supply tank at the top, and the powder dropping port is connected to the powder trough above the powder supply device 3. The powder supply device 3 is composed of a powder supply shaft 14, a gear 4, a rack 12, etc. The gear 4 is installed at both ends of the powder supply shaft 14, and the gear 4 is meshed with the fixed rack 12 to realize the clockwise and counterclockwise rotation of the powder supply shaft 14. The powder supply shaft 14 is installed on the scraper frame 5, and the scraper 6 is installed on the scraper frame 5 to scrape the powder 2 spread on the forming platform 7 and ensure uniformity and layer thickness. The scraper frame 5 is provided with front and rear powder dropping ports, which cooperate with the powder supply device 3 to complete the front and rear powder spreading, and realize the single scraper two-way powder spreading. The scraper 6 can scrape the excess powder into the front overflow powder device 11 and the rear overflow powder device 8, and collect and screen it for reuse. The pressure sensor 13 is arranged in the powder trough above the powder supply device 3 to monitor the remaining amount of powder and ensure that there is enough powder in the powder trough for two layers of powder spreading at the beginning of powder spreading.

[0036] The process of using the device for single scraper bidirectional powder spreading is as follows:

[0037] S1. The integrated scraper device for powder supply and spreading stays at the initial position for powder spreading, directly below the powder dropping device 1. The powder dropping device 1 drops an appropriate amount of metal powder 2. The powder trough above the powder supply device 3 contains the amount of powder required for two layers of printing.

[0038] S2. The integrated scraper device for powder supply and spreading starts to move forward. When the integrated scraper device for powder supply and spreading moves to the point where the gear 4 and the rack 12 are meshed, the gear 4 rotates clockwise, driving the powder supply shaft 14 to rotate clockwise. The metal powder 2 in the powder supply groove 14-1 falls from the front powder drop port onto the forming platform 7. The scraper 6 scrapes the fallen metal powder 2 to spread it evenly on the forming area, realizing powder supply and spreading while moving forward, until the integrated scraper device for powder supply and spreading moves to the front end, scraping the excess metal powder 2 into the front overflow powder device 11.

[0039] S3, the laser starts printing metal powder 2.

[0040] S4, after the printing is completed, the integrated scraper device for powder supply and spreading starts to move backwards, and when the integrated scraper device for powder supply and spreading moves to the gear 4 and the rack 12 to mesh, the gear 4 rotates counterclockwise, driving the powder supply shaft 14 to rotate counterclockwise, and the metal powder 2 in the powder supply groove 14-1 falls from the rear powder drop port onto the forming platform 7, and the scraper 6 scrapes the fallen metal powder 2 to make it evenly spread on the forming area, realizing powder supply and spreading when moving backwards, until the integrated scraper device for powder supply and spreading moves to the rear end, and scrapes the excess metal powder 2 into the rear overflow powder device 8;

[0041] S5, the laser starts printing the metal powder 2; at the same time, the integrated scraper device for powder spreading stays at the initial position of powder spreading, and the powder dropping device 1 drops an appropriate amount of metal powder 2;

[0042] S5. After printing is completed, the integrated scraper device for powder spreading moves forward again, and steps S2-S5 are repeated until the printing task is completed.

[0043] The present invention eliminates the powder falling and powder separation structure, and replaces it with an integrated powder supply and scraper powder spreading, which effectively solves the problem of uneven powder distribution and ensures that there is no powder shortage in both directions during bidirectional powder spreading. The conduction of the front and rear powder troughs is cancelled to avoid powder still falling into the forming area after powder spreading, which effectively improves the powder spreading quality.

[0044] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A powder supply and spreading integrated scraper device for 3D printing, characterized in that: It includes a powder supply device and a scraper frame, the powder supply device includes a powder supply shaft, a gear and a rack, the gear is installed at both ends of the powder supply shaft, the rack is fixed on the left and right side plates of the forming chamber, the gear is located above the rack, the gear is meshed with the rack, and the rotation of the gear drives the powder supply shaft to rotate clockwise and counterclockwise; the powder supply shaft is installed on the scraper frame, the scraper frame is provided with a front powder drop port and a rear powder drop port, and a scraper is provided below the scraper frame.

2. The integrated powder supply and spreading scraper device for 3D printing according to claim 1, characterized in that: A plurality of powder supply grooves are arranged around the powder supply shaft, and each of the powder supply grooves is arranged along the axial direction of the powder supply shaft.

3. The integrated powder supply and spreading scraper device for 3D printing according to claim 1, characterized in that: A powder dropping device is arranged above the scraper frame, the powder dropping device is connected with a powder supply tank above, and a lower powder dropping port of the powder dropping device is connected with a powder groove above the powder supply device.

4. The integrated powder supply and spreading scraper device for 3D printing according to claim 1, characterized in that: A pressure sensor is provided in the powder trough above the powder supply device, and the pressure sensor is used to monitor the amount of powder in the powder trough.

5. The integrated powder supply and spreading scraper device for 3D printing according to claim 1, characterized in that: A forming platform is arranged in the forming chamber, a front powder overflow device and a rear powder overflow device are arranged at the front and rear sides of the forming platform respectively, and a piston is arranged at the lower middle part.

6. A single scraper bidirectional powder spreading method, characterized in that: The method is implemented based on the integrated powder supply and spreading scraper device according to any one of claims 1 to 5, and comprises the following steps: S1. The integrated scraper device for powder supply and spreading stays at the initial position for powder spreading, and the powder dropping device drops an appropriate amount of metal powder, so that the powder slot above the powder supply device has the required amount of powder for two layers of printing; S2, the integrated scraper device for powder supply and spreading starts to move forward. When the integrated scraper device for powder supply and spreading moves to the meshing of the gear and the rack, the gear rotates clockwise, driving the powder supply shaft to rotate clockwise, and the metal powder in the powder supply groove falls from the front powder drop port to the forming platform. The scraper scrapes the fallen metal powder to make it evenly spread on the forming area, realizing powder supply and spreading while moving forward, until the integrated scraper device for powder supply and spreading moves to the front end, and scrapes the excess metal powder into the front overflow powder device; S3, the laser starts printing metal powder; S4. After the printing is completed, the integrated scraper device for powder supply and spreading starts to move backward. When the integrated scraper device for powder supply and spreading moves to the meshing of the gear and the rack, the gear rotates counterclockwise, driving the powder supply shaft to rotate counterclockwise, and the metal powder in the powder supply groove falls from the rear powder drop port onto the forming platform. The scraper scrapes the fallen metal powder to make it evenly spread on the forming area, realizing powder supply and spreading while moving backward, until the integrated scraper device for powder supply and spreading moves to the rear end, and scrapes the excess metal powder into the rear overflow powder device; S5, the laser starts printing metal powder; at the same time, the integrated scraper device for powder spreading stays at the initial position of powder spreading, and the powder dropping device drops an appropriate amount of metal powder; S5. After printing is completed, the integrated scraper device for powder spreading moves forward again, and steps S2-S5 are repeated until the printing task is completed.

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